A series of experiments were conducted to study impacts of the free-stream Mach number, back pressure, and bleed on the stability of a supersonic intake. The ow stability is related to the buzz phenomenon, i. e. the oscillation of all shock waves of the intake, which may also occur when the intake mass ow rate is decreasing. In this study, the intake was axisymmetric with Mach number of 2. 0. The results showed that stability margin of the intake decreased when the freestream Mach number increased for both bleedo and bleed-on cases. In the con guration without bleed, the frequency of buzz oscillation increased when the freestream Mach number decreased or when back pressure increased. By applying bleed and, consequently, preventing separation of the ow, the intake became more stable and the shocks oscillated with a smaller amplitude during the buzz phenomenon. Also, when the bleed was applied, the buzz triggering mechanism varied from the Dailey criterion to the Ferri one, which considerably changed stability characteristics of the intake.